GPR#938 cont.: fix compilation for MSVC32 (#1170)

GPR#938 broke compilation for MSVC32: the stack probing in the runtime
isn't implemented on Win32 (i386nt.asm), so the enhanced Is_in_code_area
macro should only be used in the Win64-specific part of byterun/win32.c.

Author: dra27

Changes

@@ -201,16 +201,16 @@ Working version
 
 ### Runtime system:
 
-- GPR#938: Stack overflow detection on 64-bit Windows
-  (Olivier Andrieu)
-
 - GPR#71: The runtime can now be shut down gracefully by means of the new
   caml_shutdown and caml_startup_pooled functions. The new 'c' flag in
   OCAMLRUNPARAM enables shutting the runtime properly on process exit.
   (Max Mouratov, review and discussion by Damien Doligez, Gabriel Scherer,
   Mark Shinwell, Thomas Braibant, Stephen Dolan, Pierre Chambart,
   François Bobot, Jacques Garrigue, David Allsopp, and Alain Frisch)
 
+- GPR#938, GPR#1170: Stack overflow detection on 64-bit Windows
+  (Olivier Andrieu)
+
 Next major version (4.05.0):
 ----------------------------
 

byterun/win32.c

@@ -521,16 +521,6 @@ static void caml_reset_stack (void *faulting_address)
   caml_raise_stack_overflow();
 }
 
-/* Do not use the macro from address_class.h here. */
-#undef Is_in_code_area
-#define Is_in_code_area(pc) \
- ( ((char *)(pc) >= caml_code_area_start && \
-    (char *)(pc) <= caml_code_area_end)     \
-|| ((char *)(pc) >= &caml_system__code_begin && \
-    (char *)(pc) <= &caml_system__code_end)     \
-|| (Classify_addr(pc) & In_code_area) )
-extern char caml_system__code_begin, caml_system__code_end;
-
 
 #ifndef _WIN64
 static LONG CALLBACK
@@ -565,6 +555,17 @@ static LONG CALLBACK
 extern char *caml_exception_pointer;
 extern value *caml_young_ptr;
 
+/* Do not use the macro from address_class.h here. */
+#undef Is_in_code_area
+#define Is_in_code_area(pc) \
+ ( ((char *)(pc) >= caml_code_area_start && \
+    (char *)(pc) <= caml_code_area_end)     \
+|| ((char *)(pc) >= &caml_system__code_begin && \
+    (char *)(pc) <= &caml_system__code_end)     \
+|| (Classify_addr(pc) & In_code_area) )
+extern char caml_system__code_begin, caml_system__code_end;
+
+
 static LONG CALLBACK
     caml_stack_overflow_VEH (EXCEPTION_POINTERS* exn_info)
 {